Carbureter



E. b. NEWCOMB.

CARBURETER. v APPLICATION FILED OCT. 25. 1915- I Patented-Nov; 23, 1920.

2 SHEETSSHEET I- E. C. NEWCOMB.

CARBURETER. APPLICATION men OCT. 25. I9I5.

2 SHEETS-SHEET 2.

Patented NOV. 23, 1920.

TENT

EDWARD COVER/LY NEWCOMB, OF NORTH SCITUATE, MASSACHUSETT$, ASSIGNOJR- T0 NEWCOMB CARBURETEB COMPANY, A CORPORATION 01'! NEm YOPtK.

CABBURETER.

Specification of Letters Eatent.

Patented Nov. as, man.

Application filed October 25, 1915. Serial H0. 526%.

Z '0 all w 7mm it may concern Be it known that I, EDWARD CovnnLY NEWCOMB, a citizen of the United States,

' and a resident of North Scituate, Plymouth liquid fuel in the carburetor due to conden-' sation in the carbureting chamber, at the same time leaving a sufiicient amount of liquid fuel to insure proper carburation when sudden increased demands for mixture are made upon the carbureter.

A further object of my invention is to return to the mixture in a finely atomized and aerated form the excess of the liquid fuel which condenses and accumulates in the mixing chamber.

These and other objects of my invention are more fully explained in the following description, the essential features of which are pointed out in the specification and in the appended claims.

In the drawings which are referred to herein and form a part hereof is illustrated one embodiment of my invention, the same serving in connection with the description to explain thev principles thereof.

Figure 1 of the accompanying drawing is a vertical section of my carbureter, partly in section.

Fig. 2 is a section of my residual fuel pulverizer.

Figs. 3 and 4 show its application to points in the manifold designed to correct faulty distribution of the mixture.

Similar characters refer to similar parts throughout the accompanying drawings.

Referring now to the drawings, my carbureter consists of the casing 1, having at its top an outlet for the mixture in the form of a flange-neck tube 2, adapted tobe connected to the manifold of the engine. This outlet is controlled by a butterfly throttle valve 3. The casing 1 is open at its lower end, and within this casing is secured a tubular member .6 the opening in the upper end of which is closed by a plug 4. This member 6 is open at its lower end and is providedin its side walls with a multiplicity of narrow elongated air ports 7, which dis- 6O charge into the carbureting chamber 7 These ports arefnormally closed by the piston valve 8, which is adapted to be raised bys the suctlon of the engine so asto uncoverp the ports 7 more or less in accordance with the quantity of mixture demanded by the, engine, the fit of the piston air valve being such that the air may be gradually withdrawn from the chamber above said piston valve. also establishes the vacuum under which the carbureter normally operates. In order to properly control the movements of the piston valve 8 and prevent undue fluttering,

it is provided with an upwardly extending closed tubular portion 9 fitted to the interior air port member 6, whilethe top of the latter member is closed. The fit of the piston in the member 6 being such that the air will be gradually drawn from the space above the piston and cause the piston to rise. In order to permit the piston to fall promptly and prevent an undue lowering of the vacuum when the demand for fuel is suddenly decreased, I provide 'a ball check 10 in the top wall thereof. The plug 11,. cross-shaped in cross-section so as to provide passages 11, is driven into the upper end of the chamber 5, in which the ball 11" rests to retain the ball in the chamber. The

fuel is supplied through a pipe 12 to a fioat feed chamber 13, where it is maintained at a predetermined level by the float 1d operating the valve 15. From the float feed chamber 13 the liquid fuel is supplied 95.

through the passage 16 to the jet 17, the port of which is controlled by the needle valve 18, which is secured to the piston valve 8, the needle valve being so tapered that the proper proportion of fuel will be discharged from the jet 17 into the chamber 8 of the piston 8 to properly carburet the air entering the carbureting chamber through the air ports 7 The fuel which is thus admitted to the chamber 8 of the piston valve 8 isdischarged into the carbureting chamber through the ports 8, where it is pulverizedby the streams of rapidly inrushing air entering through the ports 7. In the base of the casin 1 1 form annular ca illar 11G The weight of the piston valve 8 70 chamber 19, and at one point 1 enlarge this chamber to form a sump or well 20. It is apparent that all liquid fuel which condenses in the shell 1, which forms the carbureting chamber, svill tend to accumulate in the annular chamber 19 and the sump 20. In order to limit the quantity of fuel which may be accumulated, I provide a tube 21 extending downward through the shell 1 to point directly above the sump '20. The upper end of this tube 21 is secured, preferably by brazing, in a ring 22, which is pro vided with an annular channel 23 and is secured to the neck 28 of the carbureter by means of the gland-screw screw 24 is perforated axially to provide passages and 6, the passage 25 being of larger bore than the passage 26. The gland-screw 24 is also provided with a lat eral passage 27 communicating with the passage 25 and with the chamber 23. The operation of my device is as follows l/Vhen the throttle valve is nearly closed and the engine to which the carburetor is connected is running at slow speed the travel of the mixture is so slow that the liquid fuel tends to condense and accumulate in the'base of the carbureting chamber in disturbing be precipitated in'the manifold quantities. This tendency is increased where fuels of low volatility, such as are now commonly used, are supplied to the ca'rbureter, and it is mainly the heavier fractions of such fuel which so condense. It is, however, desirable that a limited accumulation should be provided for in a carburetor of the type shown, because when the engine has been running slowly with the throttle nearly closed, if the throttle is suddenly opened, there is a marked tendency for the fuel to because of the low rate oftravel of the mixture and the reduced vacuum in the manifold resulting from sudden opening of the throttle valve, Under these conditions, retardation of the lift of the piston valve 8 results in a sudden and considerable rise'in the vacuum in the carburetin chamber'which greatly accelerates the ve ocity of the air entering the mixing chamber through the ports 7 causing the air to pick up cumulate, the'mixture under the conditions stated becomes over-rich. lVhen the throttle yalve is partially closed the vacuum existing between the throttle valve and the engine 1S always considerably higher than the vacuum exlsting in the carbureting chamber when the carburetor is in operation, with the result that all but tlty of the liquid fuel which accumulates in the chamber 19 and the sump 20 is drawn upward through the tube 21 into the chem- The glandand pulverize the fuel ac-- ,cumulated 1n the chamber 19, thereby rea predetermined quanber 23, and thence through the passage 27 into'the'passage25 where it is met by air rushing into the passage 25 through the pas sage 26, from which point it passes through the passage 25 into the neck 28 of the carbureter in a highly atomized condition. The passage 26 having a bore aboutone-half the diameter of the bore of the passage 25, the air admitted through the passage 26 rushes at high velocity across the passage 27 and into and through the passage 25, the high vacuum beyond the throttle imparting to it sufficient velocity to properly pulverize even the heavy fractions of the liquid fuel used.

The elevation of the lower end of the tube 21 above the bottom of the sump 20 determines the amount of liquid fuel which it is allowed to accumulate in the sump 20 and the annular chamber 19.

I have found that in many of the types of manifolds in use that there is a marked tendency to distribute the mixture unevenly to the various cylinders of the motor to which the carbureter is connected, and to supply a richer mixture to certain cylinders than to the other cylinders. This condition can be corrected by so disposing the passage 25 that the mixture entering through the passage 25 will correct the distribution of the mixture through the manifold.

In Fig. 3, I have shown the pipe 21 divided at 29 into two branches, 30 and, 31, each of which is supplied with atomizers 32 and 33 similar to the atomizers in Fig. 2.

It will thus be seen that my invention willthe heavy fractions of the liquid fuel,

carry 7 are the "fractions which'tend to accumulate in the chamber 19 and the sump 20 to points in the manifold near enough to the engine cylinders so that they will be conveyed into the cylinders before they have an opportunity tov condense. As the atomizer which acts upon these fractions operates under a comparatively high vacuum this fuel is so'finely pulverized and so aerated that when delivered to the manifold at points near the engineit has little tendency to condense.

In Fig. 4, I have shown the atomizer so directed into the manifold as to correct the faulty distribution of mixture, due to the unsymmetrical shape of the manifold pipe.

Having described my invention, I claim: 1. A carburetor comprising in combination a carbureting chamber, a sump in the carburetingchamber in the path of the entering air in which a predetermined quantity of the liquid fuel which condenses in the carbureting chamber is collected and normally retained, and means for atomizing and adding the fuel so stored in said sump to the mixture when a sudden increased demand for mixture is made upon the carbu reter.

2. A carbureter comprising in combination, a carbureting chamber, air and fuel ports discharging into said carbureting chamber, a reservoir in the carbureting chamber in the path of the entering air adapted to collect and normally containa predetermined quantity of the liquid fuel which condenses in the carbureting chamber, and means for delivering the fuel so collected and normally retained to the mixture in a finely atomized condition when a sudden demand for an increased quantity of mixture is made upon the carbureter.

3. A carburetercomprising in combination, a carbureting chamber, air and fuel ports discharging intosaid carbureting chamber, a reservoir in the carbureting chamber in the path of the entering air in which the liquid fuel which condenses in the carbureting chamber is collected, means for limiting the quantity of fuel which may be retained in said reservoir, and means for delivering to the mixture in a finely atomized condition the fuel retained in said reservoir when a sudden demand for an increased quantity of the mixture is made upon the carbureter.

4. A carbureter comprising in combination a carbureting chamber, air and fuel ports discl'iarging into said carbureting chamber, a suction controlled air valve adapted to cover and uncover the air ports, a reservoir located in said carbureting chamber in the path of the air entering the carbureting chamber through the air ports in which a predetermined quantity of the liquid fuel which condenses in the carbureting chamber is collected and normally retained,

and means for checking the opening movement of said air valve constituting means for causing the air entering through said air ports to pick up and pulverize the liquid fuel normally retained in said reservoir when a sudden demand is made upon the said air ports and adjacent to said airports into which the fuel which condenses inthe 'arbureting chamber is collected, a sump communicating with said reservoir, a pipe, the upper end of which is in open communication with the neck of the carbureter beyond the throttle valve and the lower end,

of which pipe is adjacent to said sump.

Signed at New York city, in the county of New York, and State of New York, this llth day, of October, 1915.

EDWARD (IUVERLY NMWCOMB. Y Witnesses: I

lVIAnoARni A. limit, BENJAMIN T. AnnAMs. 

